Abstract: The method of fabrication of highly resistive GaN bulk crystals by crystallization from the solution of atomic nitrogen in the molten mixture of metals, containing gallium in the concentration not lower than 90 at. % and the Periodic Table group II metals: calcium, beryllium or in the concentration of 0.01-10 at. %, at the temperature 1300-1700° C., under the nitrogen pressure 0.5-2.0 GPa and in the presence of temperature gradient characterized by the temperature gradient not higher than 10° C./cm.

Abstract: A process for fabricating a multilayer crystalline structure of nitrides of metals from group III of periodic table including GaN, AlN and InN is provided. The process includes the steps of heating a group III metal (26) to a temperature T1 under an equilibrium nitrogen pressure while maintaining group III metal nitride stability to form a first crystal layer of the group III metal nitride. Thereafter the method includes the step of forming a second crystal layer (28) of the group III metal nitride by decreasing the nitrogen pressure such that the second crystal layer grows on the first layer with a growth rate slower than the growth rate of the first layer at a temperature T2 not greater than temperature T1. The second layer (28) grows on at least a portion of the first layer at a predetermined thickness under the new nitrogen pressure.